Dress Codes and You: Making it Work

Have you ever been reprimanded at work for "dressing down" or not fulfilling the standards of your organization's dress code? For many, this could be your version of a nightmare. As mentioned in previous entries, what you wear to work is a reflection of what you're capable of on the job, and there aren't many people who aim to look incompetent, especially when the boss is watching.
As simple as this all sounds, it's easy to become confused with dress codes. We've covered the basics of Business Casual and Casual Fridays, and what not to wear in the workplace. However, it's still very simple to slip up and make a wrong choice once in awhile, especially when you're first starting out.
My first job was working in a coffee shop. I noticed that many employees (including some of the management team management) wore athletic shoes and yoga pants to work. Although these items of clothing went against the dress code expectations that I had read during my training sessions, I began to wear what they were wearing. As time went on, however, I began to notice that those employees who were earning better wages and moving up in the company were dressed exactly to standard, and they looked much more professional than I did in my contraband gear. From then on I decided that I was going to dress the way that they did, according to the rules. Needless to say, this paid off for me (literally).
How do you feel about this story? Have you ever felt pressure from your colleagues to dress a certain way, even if it was against company standards? Do you think that what you wear to work is directly related to job advancement?